Evolution of structure, magnetism and ferroelectricity in the (1-x)BiFeO3-xBa0.5Sr0.5MnO3(0≤x≤1) solid solutions

The structural, magnetic, ferroelectric and electrical properties of a series of (1-x)BiFeO3-xBa0.5Sr0.5MnO3 (0 ≤ x ≤ 1) solid solutions have been studied. The crystal structure of these samples changes from rhombohedral R3c (0 ≤ x ≤ 0.1) to cubic Pm3¯m (0.16 ≤ x ≤ 0.5) and finally to hexagonal P63/mmc (0.7 ≤ x ≤ 1.0) with increasing x. Two local maxima in the remnant magnetization Mr and coercive field Hc are observed in the vicinity of the two structural phase boundaries, i.e., x = 0.16 and 0.7. The samples with x ≤ 0.1 exhibit multiferroicity with magnetoelectric effect, while the samples with x ≥ 0.16 possessing centrosymmetric crystal structure show semiconducting behavior. The existence of low-valence Mn3+ ions associated with oxygen vacancies is found to influence significantly the structure, magnetism and ferroelectricity in these samples.